We can simplify the observables and rewrite them in the following
form [1]}, [2]},
\(&&s=\theta _{\infty }e^{\frac{\bar{b}}{\bar{a}}-\frac{2\pi }{\bar{a}}},\nonumber \\&&\mathcal {R}=e^{\frac{2\pi }{\bar{a}}}.\) 
